Continuous passive motion (“CPM”) therapy is used in recovery following joint trauma and has been found to have beneficial results in the rehabilitation of injured joints and/or limbs. Continuous passive motion can also be used for treatment of other bone and muscular disorders, such as arthritis. For patients recovering from extensive joint surgery any attempt at joint motion causes extreme pain. Consequently, patients tend to avoid substantial movement of the limb. This immobilization allows the tissue around the joint to become stiff and scar tissue to form. These undesirable effects lead to limited range of motion in the joint and prolong physical therapy before the joint and limb regain substantial range of motion, neurological function and muscle function. If full range of motion of the joint and limb is not achieved in the immediate or early postoperative period, then the full range of motion may never be recovered.
CPM devices are often used during early phases of postoperative rehabilitation to provide passive motion to the treated joint and limb, to control postoperative pain, and reduce inflammation. Typical CPM devices move a patient's limb and joint through a predetermined range of motion without exertion by the patient. The passive motion acts to pump blood and interstitial fluid away from the joint and surrounding tissue. It also acts to increase absorption of synovial fluid by the cartilage, which provides nutrients. As a result, CPM devices can reduce joint stiffness and improve venous blood flow.
Several CPM devices are available for use in therapy for the rehabilitation of the knee. Conventional devices commonly include a stationary base or frame, a femur support which supports the upper part of the leg, a tibia support which supports the lower part of the leg, a foot support for supporting the foot, and a drive system. The femur and tibia supports are pivoted with respect to each other, and are supported above the stationary base.
These devices however suffer from several disadvantages. Among these is the fact that conventional devices are large, cumbersome, complicated, and heavy. For example, they can be very difficult for a patient in a hospital bed or a medical professional to move out of the way when it is necessary to change the sheets or bed linens. They are also not designed for easy transportability, some weighing in excess of 34 kg (75 pounds) and/or too large and awkward to transport in a standard vehicle. Further, conventional devices also have been generally too expensive for individuals to purchase for home use.
Another disadvantage is that traditionally a knee brace or other type of brace is worn separately from the CPM device, and is removed prior to CPM therapy. For instance, when it is time to exercise the limb or joint, the patient typically removes their brace or cast and places the injured limb or joint on soft goods of the CPM. The patient and/or medical professional must then ensure that the mechanics of the brace and the CPM device are not in conflict such that they do not cause damage to the patient's limb or joint. This process can be time-consuming, uncomfortable, and even dangerous to the patient if not done properly.
Removal of the knee brace prior to CPM therapy may also be physically difficult and painful. The effectiveness of a therapy is dependent on the ease in which the therapy may be applied. If it is difficult for a therapy recipient to self-apply a therapy, the opportunity to receive therapy may be diminished. Furthermore, if therapies are complicated and/or uncomfortable, a therapy recipient is less likely to undergo the therapy, although it may be beneficial.
There is a need for a CPM device that is transportable, lightweight, affordable, and versatile. There also exists a need for a CPM device that allows a brace to be quickly connected and disconnected to the CPM device to avoid requiring the user to remove the brace during CPM therapy.